Searchlight



Aug. 31, 1937. KIEFER 2,091,819

SEARCHLIGHT Filed Feb. 5, 1935 Inventor: Johannes Wafer, b WW 3 3 His Attorne y.

Patented Aug. 31, 1937 UNITED STATES PATENT OFFICE SEARCHLIGHT Johannes Kiefer, Berlin-Charlottenburg,

Ger-

many, assignor to General Electric Company, a corporation of New York 3 Claims.

My invention relates to searchlights, and more particularly to an electrode holder and feed mechanism therefor.

One object of my invention is to provide an im- 5 proved rotating and feed mechanism for the positive electrode.

Another object of my invention is to provide an improved reversible feed mechanism for searchlight electrodes.

10 For a better understanding of my invention, to-

gether with other and further objects thereof, reference is had to the following description, taken in connection with the accompanying drawing, and its scope will be pointed out in the appended 15 claims.

The single figure in the drawing illustrates in vertical cross section through its center an electrode holder built in accordance with my invention. The holder comprises a frame I bolted to 20 and supported by a pedestal 2. Frame I is provided at its forward end with a nose piece 3 through which an electrode 4 projects and in which a brush 5 contacts with the electrode 4 and conducts current thereto. The electrode 4 is 25 rotated by and fed through a pair of tubular members B and l rotatably mounted in the frame I and rotatable with respect to each other. The member 6 is supported by a pair of ball bearings 8 and 9 comprising a sleeve l mounted in the 30 frame I and fastened thereto by a screw H, ro-

tating collar l2 and disc l3. It is driven by a gear wheel M meshing with a pinion l rotatably mounted in bracket l6 on a shaft H. The bracket I6 is integral with the pedestal 2. Concentric 5 with the tube 6 and rotatably mounted therein is tube 1. The electrode 4 slides within this tube and is controlled by a pair of feed rolls l8 and I9 mounted rotatably in brackets 20 and 21 projecting forward from a flange 22 at the front end of 40 the tubular member 1. The feed rolls are provided with sharp teeth for engaging the carbon electrode. The teeth are further shaped laterally to form a portion of a worm gear and for engaging the threads of a drive sleeve. A pair of ball 45 bearings 23 and 24 separate the tubular member 1 from, the member 6 and permit the rotation of the member l within the member 6. A gear 25, attached to the back end of the tubular member I, meshes with a pinion 26 which is also mounted 50 on shaft I1 and rotated thereby. The gear 25 is of greater diameter and has a greater number of teeth than the gear 14, and pinions l5 and 26 are approximately of the same diameter and have an equal number of gear teeth, so that when the 5 two pinions l5 and 26 are rotated in unison by the shaft ll the transmission ratio is greater for the member 1 and is therefore rotated slower than member 6 and the two members rotate with respect to each other. The pinion 2B is mounted on shaft I'I directly under pinion I5 and rests upon 5 a ball bearing 21 on the upper side of bracket IS. A second ball bearing 28 is mounted on the underside of the bracket and a disc 29 mounted on the shaft I! locks the shaft against axial displacement.

At the forward end of member 6, an enlarged tubular portion, or sleeve, 30 projects over the feed rolls l8 and I9 and is provided with an internally threaded flange 3| at its forward end. The teeth of the flange engage the teeth of the feed rolls, which, as above explained, are properly shaped for this purpose.

In operation the shaft I1 is rotated by any suitable prime mover and thereby rotates the members 6 and 'I through the pinions l5 and 26 and the engaging gears l4 and respectively. Due to the difference in the two ratios of transmission, the member I is caused to rotate faster than the member 6 whereby the feed rolls l8 and [9 are moved along the threads on the flange 3|. This 25 causes a rotation of the feed rolls and consequently a forward movement, or advance, of the electrode. By simply reversing the rotation of shaft H, the rotation of the feed rolls is reversed and the electrode is retracted.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electrode holder for searchlights including a rotatably mounted sleeve for guiding an electrode, a second sleeve mounted rotatably and coaxiaily with said first sleeve, feed rolls held on said first sleeve and a threaded collar for engaging said feed rolls attached to said second sleeve,

a pair of concentric gears mounted on corresponding ends of said sleeves and a pair of pin- 40 ions mounted on a single drive shaft for driving said gears at unequal speeds whereby an electrode may be simultaneously advanced and rotated.

2. A holder for a searchlight electrode including a. rotating and feeding mechanism comprising a sleeve provided with feed rolls, a second sleeve coaxial with said first sleeve provided with a threaded portion for engaging the said feed rolls, a pair of concentric gears, one having a greater number of teeth than the other attached to the corresponding ends of said sleeves, and a common drive shaft provided with pinions having equal numbers of teeth for engaging said gears and driving said sleeves respectively at different speeds whereby the feed rolls are turned about their respective axes due to the relative motion between said sleeves.

3. An electrode holder for searchlights including a rotatably mounted sleeve for guiding an electrode, a second sleeve mounted rotatably and coaxially with said first sleeve, feed rolls mounted on said first sleeve and provided with teeth adapted to engage an electrode and axially formed to comprise portions of a Worm gear, an

10 internally threaded collar attached to said sec- J OHANNES KIEFER. 

